1. Field
The present disclosure generally relates to multi-chip modules (MCMs) and techniques for fabricating MCMs. More specifically, the present disclosure relates to an MCM that includes positive features that are self-populated into negative features in a substrate by using hydrophilic and hydrophobic layers.
2. Related Art
Engineers have recently proposed using multi-chip modules (MCMs) to integrate a 3-dimensional (3D) stack of semi-conductor chips. A major challenge associated with such MCMs is aligning the chips with respect to each other.
One approach to aligning the chips uses positive features (such as spherical balls) to mechanically couple pairs of negative features (such as pits) on facing surfaces of chips in the MCM. In particular, the positive features may mate with pairs of the negative features, thereby aligning and coupling the chips to each other.
However, it can be expensive and time consuming to position the positive features in the negative features. For example, a pick-and-place assembly technique can be used to put the positive features in the negative features during fabrication of an MCM, but the process is typically slow, which can significantly increase the cost of the MCM.
Hence, what is needed is an MCM and a fabrication technique that does not suffer from the above-described problems.